I'm trying to do some live streaming in Ubuntu 12.10, but I'm having some problems with audio. More specifically, the quality is complete garbage and it's at least 10 seconds out of sync with the video.

I'm using an excellent guide found here to set up my loopback devices so that I can combine the desktop audio with the microphone input. It seems to work, as I'm able to stream both audio and video to Twitch.tv. But, as I said, the audio quality is terrible. The microphone audio is very, very low, but if I increase it, I get a horrible garbled sound that is absolutely unbearable. Nothing like that is present during VoIP calls or when recording sound alone with the sound recorder, so it's not an issue with the microphone itself. The entire audio stream is also delayed about 10-15 seconds compared to the video stream.

Can you post output from top and iotop while streaming and getting awful quality? (Need to make sure it's not a simple case of CPU and/or I/O contention.)
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Jim SalterNov 25 '12 at 21:55

@JimSalter There, I've added links to the output of both top and iotop (I had to host them on external sites, as I exceeded the character limit by about 100,000 characters).
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Tommy BrunnNov 26 '12 at 14:13

1 Answer
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I suspect this is the key here. avconv seems to be running single-threaded and is completely pegging the CPU core it's running under. What sort of video chipset does your system have? You may need to get vdpau (assuming you have nvidia) running in order to get things running properly.

It's possible but seems unlikely to me that the problem could be the audio itself - you might try only capturing one channel rather than two and at a lower bitrate, to see if that helps. I really think it's going to be the video that's the issue, though.